Broadband Dual-Polarized Waveguide Slot Filtenna Array With Low Cross Polarization and High Efficiency

Abstract

A broadband waveguide slot filtenna array with low cross polarization and high efficiency is presented for dual-polarization applications. The vertical polarization radiation is achieved by offsetting longitudinal slots on the ridged waveguide, while the horizontal polarization radiation is achieved by V-shaped slots on the ridged waveguide. Two polarization ridged waveguide linear arrays combine to obtain dual-polarized radiation with cross-polarization levels under -43 dB in wide angles. To extend the bandwidth of the array, each 1×16-element linear array is separated into two 1 × 8-element arrays, which are fed by a two-way ridged waveguide divider via H-shaped slot couplings. The evanescent-mode ridged waveguide filters are integrated into a two-way ridged waveguide divider that suppresses the out-of-band signal interference. The signals of the interference bands are suppressed effectively, which are -25 dB lower than that of the operation band. Furthermore, 16 pairs of dual-polarized linear arrays are designed, fabricated, and measured. The results show that the array has perfect properties such as bandwidth, polarization purity, efficiency, and immunity to interference.